Antiviral antibiotic BU-3889V

ABSTRACT

Production of an antiviral antibiotic complex, BU-3889V and its bioactive components A 1 , A 2 , A 3 , D 1 , D 2  and D 3 , by fermentation of a BU-3889V producing strain of the new microorganism Amycolatopsis orientalis ATCC-53884 is disclosed. Complex BU-3889V is recovered and the components separated by the use of ion exchange chromatography techniques. The bioactive components are characterized by their physico-chemical characterizing properties. The products have been found to be effective to inhibit viruses including herpes simplex virus, human immunodeficiency virus (HIV) and influenza virus.

CROSS-REFERENCE TO RELATED APPLICATIONS

application is a continuation-in-part of our co-pending application Ser. No. 536,746 filed June 14, 1990, now abandoned, which is a continuation-in-part of application Ser. No. 377,036 filed July 10, 1989, now abandoned.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a new antiviral antibiotic complex and its components. It relates also to methods of producing the novel products utilizing novel strains of the species Amycolatopsis orientalis, to their use as antiviral agents and to pharmaceutical compositions containing them.

SUMMARY OF THE INVENTION

This invention is a new water soluble antiviral antibiotic complex designated BU-3889V, and its antibiotically active components which are produced by fermenting a BU-3889V producing strain of Amycolatopsis orientalis ATCC-53884 or a mutant thereof, in an aqueous fermentation culture nutrient medium containing assimilable sources of nitrogen and carbon under submerged aerobic conditions until a substantial amount of the antibiotic complex of BU-3889V is produced by the organism in the fermentation culture nutrient medium. The antibiotic components produced by the above identified organism are recovered by separating the water-insoluble material from the fermentation broth to obtain a fermentation supernatant liquid containing the water soluble antibiotic activity from which the novel antibiotic complex and its components are isolated by chromatographic techniques.

DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 5 show the high pressure liquid chromatography (HPLC) scan of the BU-3889V complex and of components A₁, A₂, A₃, and D₁, respectively.

FIGS. 6 to 9 show the infrared (IR) absorption spectrograph of components A₁, A₂, A₃, and D₁ in a potassium bromide pellet.

FIG. 10 shows the effect of A₁ and D₁ on the expression of HIV antigen in infected cells.

FIG. 11 shows the effect of A₁ and D₁ on cell growth of MT-4 cells and the inhibition effect on the virus-induced cytopathic effects in HIV-infected MT-4 cells.

FIGS. 12 to 14 show the ¹ H-NMR spectra of A₁, A₃ and D₁, respectively.

FIG. 15 shows some of the partial structure of A₁.

FIGS. 16 and 17 show the infrared (IR) absorption spectrograph of components D₂ and D₃, respectively, in a potassium bromide pellet.

FIGS. 18 and 19 show the ¹ H-NMR spectra of components D₂ and D₃, respectively.

FIG. 20 shows the high pressure liquid chromatography (HPLC) scan of a mixture of BU-3889V D₁, D₂ and D₃ components.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the present invention is a new antiviral antibiotic complex, designated BU-3889V, which is produced by fermenting a BU-3889V producing strain of Amycolatopsis orientalis, most preferably the strain Amycolatopsis orientalis ATCC-53884.

In another aspect, the invention includes the antiviral components BU-3889V A₁, BU-3889V A₂, BU-3889V A₃, BU-3889V D₁, BU-3889V D₂ and BU-3889V D₃, isolated from the complex.

In another aspect, the invention includes pharmaceutical compositions containing the complex or at least one of the components together with a pharmaceutically acceptable excipient.

In another aspect, the invention includes a process for producing and isolating the novel aforesaid products.

In still another aspect, the invention includes a process for inhibiting the growth of viruses comprising contacting such viruses with a growth inhibitory effective amount of one or more of the novel products of the invention.

In yet another aspect, the invention is the novel microorganism Amycolatopsis orientalis ATCC-53884 as provided by the present invention in the form of a biologically pure culture.

The new culture Amycolatopsis orientalis Q427-8 was submitted to the American Type Culture Collection, Rockville, Md., and given the designation ATCC-53884. The permanency of the deposit of this culture at The American Type Culture Collection at Rockville, Md., and ready accessibility thereto by the public are afforded throughout the effective life of the patent in the event the patent is granted. Access to the culture is available during pendency of the application under 37 C.F.R. 1.14 and 35 U.S.C. 112. All restrictions on the availability to the public of the culture deposited will be irrevocably removed upon granting of the patent.

The Microorganism 1. Taxonomy

An actinomycete, strain ATCC-53884, which produces the antiviral antibiotic BU-3889V complex was isolated from a soil sample collected in Maharastra State, India. The morphological, cultural and physiological characteristics, and cell chemistry of strain ATCC-53884 indicate that the strain is classified as Amycolatopsis, a genus of nocardioform actinomycetes. Based on the diagnostic physiological characteristics, it is a strain of Amycolatopsis orientalis.

2. Morphology

Substrate and aerial hyphae are long, monopodially branched, and partially zigzag-shaped. Partial fragmentation of substrate hyphae occurs at the periphery of intact colony after incubation for 3 weeks. The aerial hyphae bear long straight chains of oblong spores (0.6×0.6-3.0 m) with a smooth surface.

Motile spores, sporangia, or synnemata are not formed.

3. Cultural and Physiological Characteristics

The colorless or yellowish colony is covered with white aerial mycelium. Carotinoid yellow pigment is formed, but melanoid and other distinct pigments are not formed.

The temperature range for growth is 19° C. to 40° C. Among 25 sugars examined, acid production is observed in 22 sugars, but not with D-melezitose, cellulose, and dulcitol.

The cultural characteristics are shown in Table 1. The diagnostic physiological characteristics (Table 2) which were determined are based on the methods of Gordon, et al., J. Gen. Microbiol., 109. pp. 69-78, 1978, and Lechevalier, et al., Int. J. Syst. Bacteriol., 36, pp. 29-37, 1986.

4. Chemotaxonomy

Whole cell hydrolysate contains meso-diaminopimelic acid, galactose, arabinose, and rhamnose. Hence, the cell wall belongs to Type IV_(A). Phospholipids contain phosphatidylethanolamine which showed 2 spots on thin layer chromatography (TLC), phosphatidylglycerol, and phosphatidylinositol. Therefore, the strain belongs to Type P-II. Glycolate test is negative (N-acyl type of peptidoglycan: acetyl). Mycolic acid is absent, and menaquinone MK-9 (H₄) is observed as a major component.

5. Taxonomic Position

Strain ATCC-53884 belongs to mycolateless nocardioform actinomycetes. Among 11 genera of nocardioforms, (see Lechevalier, et al., Loc. cit, and Lechevalier, et al., in Bergey's Manual of Systematic Bacteriology, Volume 2, pp. 1458-1506, 1986, Williams & Wilkins, Baltimore, Md.), strain ATCC-53884 is chemotaxonomically placed in Amycolatopsis which includes four species, A. orientalis, A. orientalis subsp. lurida. A. mediterranei. A. rugosa, and A. sulphurea. Physiological characteristics of strain ATCC-53884 indicate that the strain could be classified as Amycolatopsis orientalis.

                                      TABLE 1                                      __________________________________________________________________________     Cultural characteristics of strain ATCC 53884                                  Medium        Growth Aerial mycelium                                                                           Reverse color                                                                             Pigment                             __________________________________________________________________________     Sucrose-nitrate agar                                                                         Moderate                                                                              Poor; white (263)                                                                         Light yellow (86)                                                                         None                                (Czapek-Dox agar)                                                              Tryptone-yeast extract broth                                                                 Moderate and                                                                            --         --       Pale yellow (89)                    (ISP No. 1)   not turbid                                                       Yeast extract-malt extract                                                                   Good   Abundant; white (263)                                                                     Brilliant orange                                                                          Light orange yellow (70)            agar (ISP No. 2)                yellow (67)                                    Oatmeal agar (ISP No. 3)                                                                     Moderate                                                                              Moderate; white (263)                                                                     Colorless  None                                Inorganic salts-starch agar                                                                  Moderate                                                                              Moderate; white (263)                                                                     Vivid orange yellow                                                                       Pale yellow (89)                    (ISP No. 4)                     (66)                                           Glycerol-asparagine agar                                                                     Moderate                                                                              Moderate; white (263)                                                                     Pale yellow (89)                                                                          None                                (ISP No. 5)                                                                    Peptone-yeast extract-iron                                                                   Poor   No or scant; whitish                                                                      Colorless  None                                agar (ISP No. 6)                                                               Tyrosine agar (ISP No. 7)                                                                    Moderate                                                                              Moderate; white (263)                                                                     Pale yellow (89)                                                                          Pale yellow (89)                    Glucose-asparagine agar                                                                      Poor   Poor; white (263)                                                                         Yellowish white (92)                                                                      None                                Nutrient agar Poor   Poor; white (263)                                                                         Colorless  None                                __________________________________________________________________________      Observation after incubation at 28° C. for 3 weeks.                     Color names: ISCCNBS colorname charts                                    

                  TABLE 2                                                          ______________________________________                                         Physiological characteristics of strain ATCC-53884                             ______________________________________                                         Decomposition of:                                                              Adenine              -                                                         Casein               +                                                         Hypoxanthine         +                                                         Tyrosine             +                                                         Xanthine             +                                                         Decarboxylation of:                                                            Benzoate             -                                                         Citrate              - or TR                                                   Mucate               -                                                         Succinate            +                                                         Tartrate             - or TR                                                   Production of:                                                                 Nitrate reductase    -                                                         Amylase              + (w)                                                     Urease               +                                                         Esculinase           +                                                         Gelatinase           +                                                         Phosphatase          ND                                                        Tyrosinase           -                                                         Growth on or in:                                                               Lysozyme broth       -                                                         Salicylate           ND                                                        5% NaCl              +                                                         Growth at:                                                                     10° C.        -                                                         45° C.        -                                                         Acid produced from:                                                            Adonitol             +                                                         D(-)Arabinose        +                                                         L(+)-Arabinose       +                                                         Cellobiose           +                                                         Dextrin              ND                                                        Erythritol           +                                                         D-Galactose          +                                                         D-Glucose            +                                                         Inositol             +                                                         Lactose              +                                                         Maltose              ND                                                        D-Mannitol           +                                                         D(+)-Melezitose      -                                                         Melibiose            +                                                         α-Methyl-D-glucoside                                                                          +                                                         Raffinose            +                                                         Rhamnose             +                                                         Salicin              ND                                                        D-Sorbitol           +                                                         Sucrose              ND                                                        Trehalose            +                                                         D-Xylose             +                                                         Utilization of:                                                                Cellulose            -                                                         Dulcitol             -                                                         D-Fructose           +                                                         D-Mannose            +                                                         Salicin              + (w)                                                     Soluble starch       +                                                         Sucrose              +                                                         Temperature:                                                                   Growth range         19° C.-40° C.                               Optimal growth       25° C.-34° C.                               No growth            16° C. & 43° C.                             Tolerance to:                                                                  NaCl,                                                                          1%-8%                +                                                         9%                   -                                                         pH, 5.0-11.5         +                                                         ______________________________________                                          Abbreviations                                                                  TR: trace, + (w): weakly positive, ND: not determined                    

6. Partial Structures and NMR Spectra

The ¹³ C-NMR (Nuclear Magnetic Resonance) spectra in Table 3 indicate 39 carbon signals in BU-3889V A₁ and 33 signals in BU-3889V D₁. The spectra of A₁ and D₁ correspond well except that resonances around δ 99.1, 72.0, 70.4, 70.3, 69.3, and 61.9 of BU-3889V A₁ are absent in BU-3889V D₁. Based on the ¹ H-NMR spectra (Table 4) and 2D-NMR analysis, these carbon signals are considered to be those of a galactopyranoside molecule.

The ¹ H-NMR spectra taken at 400 MHz, D₂ O, or DMSO-d₆ of A₁, A₃, and D₁ are shown, respectively, in FIGS. 12, 13, and 14.

These findings suggest that A₁ is a galactoside derivative of D₁. In fact, upon mild acid methanolysis, A₁ yields D₁ and methyl D-galactoside. Extensive examination of the ¹ H-¹ H COSY spectrum of A₁ reveals the presence of the partial structures shown in FIG. 15.

The molecular weights of BU-3889V A₁ and D₁ are assigned as 1504 and 1180, respectively, by negative fast atom bombardment mass spectrometry. The 324 mass unit difference between them corresponds to 2 moles of galactose. Interpretation of these data shows that BU-3889V A₁ is a dimeric structure of two 39 carbon compounds which are composed of the partial structures shown in FIG. 15. The ¹ H- and ¹³ C-NMR spectra of BU-3889V A₂ and A₃ are very similar to those of BU-3889V A₁ differing only in the aldehyde signals.

The spectra of BU-3889V A₃ lacks the aldehyde proton (δ: 9.50) and carbon signal (δ: 198.4) observed in those of BU-3889V A₁ but shows a hydroxymethyl signal (¹ H, δ: 4.24 & 4.14 and ¹³ C, δ: 65.1) which is not observed in BU-3889V A₁. The spectra of BU-3889V A₂ exhibits both the aldehyde and hydroxymethyl signals with about a half integration of those of other common signals. The spectral data suggest that BU-3889V A₂ and A₃ are reduced analogs of BU-3889V A₁ with one (A₂) or both (A₃) of the 2 aldehydes of the latter being reduced to --CH₂ OH.

                  TABLE 3                                                          ______________________________________                                         .sup.13 C-NMR data of BU-3889V A.sub.1 and D.sub.1                                         BU-3889V A.sub.1   BU-3889V D.sub.1                                Carbon      (D.sub.2 O)        (DMSO-d.sub.6)                                  ______________________________________                                          1          199.3   s          197.3 s                                          2          198.4   d          194.6 d                                          3          198.2   s          193.5 s                                          4          196.7   s          192.7 s                                          5          183.7   s          181.7 s                                          6          177.1   s          174.0 s                                          7          176.8   s          173.9 s                                          8          157.5   d          154.5 d                                          9          145.6   d          146.4 d                                         10          143.4   d          143.1 d                                         11          143.2   s          142.4 s                                         12          137.9   s          141.4 s                                         13          137.8   d          137.9 d                                         14          135.3   s          133.3 s                                         15          132.7   d          126.6 d                                         16          130.3   d          125.7 d                                         17          127.6   d          124.2 d                                         18          99.9    s          96.8  s                                         19          99.1    d          --                                              20          98.0    s          93.7  s                                         21          87.9    s          85.0  s                                         22          87.5    s          83.3  s                                         23          72.0    d          --                                              24          70.8    t          62.4  t                                         25          70.4    d          --                                              26          70.3    d          --                                              27          69.3    d          --                                              28          61.9    t          --                                              29          45.7    s          45.5  s                                         30          45.4    s          43.5  s                                         31          36.6    t          36.0  t                                         32          32.8    t          33.6  t                                         33          28.7    d          27.5  d                                         34          25.5    d          25.0  d                                         35          22.8    q          25.3  q                                         36          22.5    q          21.7  q                                         37          20.9    q          20.3  q                                         38          18.5    q          19.1  q                                         39          12.6    q          12.1  q                                         ______________________________________                                    

                  TABLE 4                                                          ______________________________________                                         .sup.1 H-NMR data of BU-3889V A.sub.1 and D.sub.1 (400 MHz)                    BU-3889V A.sub.1   BU-3889V D.sub.1                                            (D.sub.2 O)        (DMSO-d.sub.6)                                              ______________________________________                                         δ                                                                            9.50   (1H, s)         δ                                                                             9.52 (1H, s)                                   7.38   (1H, d, J=15.8)    7.52   (1H, d, J=15.4)                               6.78   (1H, d, J=15.8)    6.99   (1H, s)                                       6.61   (1H, d, J=14.7)    6.80   (1H, d, J=15.8)                               6.54   (1H, br-s)         6.77   (1H, d, J=11.6)                               6.31   (1H, dd, J=10.3 & 14.7)                                                                           6.11   (2H, m)                                       6.20   (1H, d, J=10.3)    5.21   (1H, s)                                       5.66   (1H, s)            4.04   (2H, s)                                       4.98   (1H, d, J=4.0)     2.71   (1H, m)                                       4.50   (1H, d, J=10.3)    2.38   (2H, m)                                       4.11   (1H, d, J=2.9)     1.72   (3H, s)                                       4.05   (1H, dd, J=3.3 & 10.3)                                                                            1.68   (1H, m)                                       3.93   (1H, t, J=6.2)     1.41   (1H, m)                                       3.86   (1H, d, J=10.3)    1.27   (1H, m)                                       3.82   (1H, dd, J=4.0 & 10.3)                                                                            1.24   (3H, s)                                       3.74   (2H, m)            1.16   (3H, d, J=7.2)                                2.87   (1H, m)            1.01   (3H, d, J=6.8)                                2.42   (1H, m)            0.98   (3H, s)                                       2.24   (1H, m)                                                                 2.14   (1H, m)                                                                 1.93   (1H, m)                                                                 1.77   (3H, s)                                                                 1.66   (1H, d, J=15.8)                                                         1.38   (3H, s)                                                                 1.20   (3H, d, J=7.3)                                                          1.06   (3H, d, J=6.6)                                                          0.92   (3H, s)                                                                 ______________________________________                                    

Component BU-3889V D₁, subsequent to the filing date of patent application Ser. No. 377,036 filed July 20, 1989, was found by HPLC to contain two additional components designated BU-3889V D₂ and BU-3889V D₃ in addition to BU-3889V D₁ (see FIG. 20). The physico-chemical and biological properties of these new component antibiotics are described below along with their methods of preparation.

Preparation, Isolation, and Purification of Antibiotic Products

The process for producing the antiviral antibiotic complex BU-3889V and the components A₁, A₂, A₃, D₁, D₂ and D₃ according to the present invention comprises the steps of:

(a) cultivating Amycolatopsis orientalis ATCC-53884 or a BU-3889V-producing variant or mutant thereof in an aqueous fermentation culture nutrient medium containing assimilable sources of nitrogen and carbon under submerged aerobic conditions until a substantial amount of the complex BU-3889V containing components designated A₁, A₂, A₃, D₁, D₂ and D₃ is produced by the organism in the fermentation culture medium;

(b) separating the mycelium and other undissolved residues from the fermentation culture medium to obtain a supernatant liquid which contains antibiotic activity;

(c) adsorbing the antivirally active components contained in the supernatant liquid from step (b) on a nonionic ion exchange resin;

(d) separating the antivirally active components;

(e) adsorbing the antivirally active components on a silica gel column;

(f) separating and recovering the BU-3889V complex;

(g) separating and recovering the components A₁, A₂, A₃, D₁, D₂ and D₃ from the antiviral antibiotic complex, BU-3889V, by at least one conventional adsorption and crystallization technique.

The assimilable carbon source for use in the aqueous fermentation culture medium may be a carbohydrate such as, for example, glucose, ribose, galactose, fructose, mannose, sucrose, lactose, soluble starch, and glycerol, to name a few.

The assimilable nitrogen source for use in the aqueous fermentation culture medium may be any one of such conventionally known sources, including fish meal, soybean meal, corn steep liquor, peptones, meat extract, peanut flour, yeast extract, and ammonium salts to name but a few.

Inorganic salts, such as sodium chloride, potassium chloride, magnesium sulfate, calcium carbonate, phosphates, and the like, may be added if desired. In addition, trace elements, such as copper, manganese, iron, zinc, and the like, may be added if desired or they may be supplied as minor or trace impurities of other constituents in the fermentation media.

The incubation temperature may be any temperature at which a BU-3889V-producing strain is able to grow. Preferably, the incubation temperature is about 19°-40° C., more preferably about 25°-35° C., and most preferably about 27°-32° C.

A neutral or nearly-neutral initial pH, e.g. pH about 6-7, is preferably employed in the fermentation media, and production of the antibiotic complex by fermentation is generally carried out for a period of about 2-10 days. Ordinarily, optimum production is achieved in about 6-8 days. For the preparation of relatively small amounts of antiviral antibiotic complex, shake flasks and surface culture can be employed, whereas for relatively large amounts, submerged aerobic culture in sterile fermentation tanks is preferred. When tank fermentation is to be carried out, it is desirable to produce a vegetative inoculum in a nutrient broth by inoculating the broth culture with a spore from the organism and, when a young active vegetative inoculum has been obtained, transferring the inoculum aseptically to the fermentation tank medium. Aeration in tanks and bottles may be provided by forcing sterile air through or onto the surface of the fermentation medium. Further agitation of the medium may be provided by a mechanical impeller and an antifoaming agent such as is conventional in the art, e.g. lard oil, may be added as needed.

The production of the BU-3889V complex in the fermentation medium may be followed readily during the course of the fermentation by the dye-uptake assay with herpes simplex virus type I.

After optimum fermentation broth potency has been obtained (as determined by the above-described assay method), the mycelium and undissolved residues are separated from the fermentation broth by conventional means such as filtration and centrifugation to obtain a supernatant liquid (or filtrate) which contains antibiotic activity. The components having antibiotic activity can be recovered from the supernatant liquid by employing conventional adsorption techniques. The adsorbents which can be employed most advantageously are the nonionic macroreticular polymer resins including, for example, Diaion HP-20 resin (Diaion is a trademark owned by Mitsubishi Chemical Industries, Ltd., Tokyo, Japan) commercially available from Nippon Rensui Co., Japan.

In one preferred embodiment, the supernatant liquid, neutralized, if necessary to pH 7, is stirred with a nonionic resin such as Diaion HP-20 to adsorb the components having antibiotic activity from the supernatant liquid. These components include the BU-3889V complex and its A₁, A₂, A₃, D₁, D₂ and D₃ constituents. The resin is washed with water and a lower water miscible alkanol and the activity eluted with, e.g. aqueous acetone. Those effluents exhibiting activity in the dye-uptake assay are combined and concentrated in vacuo to an aqueous solution which is adjusted to pH 7.0, applied to a Diaion column and developed with water and lower alkanol. Evaporation of the bioactive alkanol eluates under reduced pressure to a concentrated aqueous solution followed by washing with a polar liquid such as an organic ester, and concentration of the aqueous layer under reduced pressure affords the crude BU-3889V.

Subsequent operations to obtain the A₁, A₂, A₃, D₁, D₂ and D₃ components are conducted in a dark room.

Preparation of BU-3889V A₁, BU-3889V A₂, BU-3889V A₃, BU-3889V D₁, BU-3889V D₂ and BU-3889V D₃

Components A₁, A₂ and A₃, in the presently preferred procedure, are obtained from the crude, solid BU-3889V by first combining the crude mixture with silica gel and loading the mixture on the top of a silica gel column (Wakogel C-200 brand silica gel commercially available from Wako Pure Chemicals Industries, Ltd., Japan) and eluting with a n--BuOH--n--PrOH--NH₄ OH--H₂ O mixture. The selected fractions are monitored by the antiviral assay and TLC. They are concentrated under reduced pressure and the residue are dissolved in phosphate buffer (pH 7.0) and subjected to reversed phase C₁₈ column chromatography (YMC - ODS, AM type, commercially available from Yamamura Chem. Lab. Co., Ltd., Japan). The column is developed with the same buffer containing increasing amounts of methanol. The eluate is followed with TLC. The first active fractions containing A₃ are concentrated to a small volume, and purified and isolated utilizing a Diaion HP-20 column. The second and third active eluates are similarly treated to obtain the A₁ and A₂ components. The A₁ component may be further purified by HPLC.

Preparation of BU-3889V D₁, BU-3889V D₂ and BU-3889V D₃

A mixture of D₁, D₂ and D₃ components is obtained from early active fractions from the silica gel column which are evaporated to dryness to yield a crude solid mixture of the three components. This crude product is dissolved in 50% aqueous t-butanol and subjected to a reversed phase C₁₈ column chromatography. The column is developed with 0.022M phosphate buffer solution containing an increasing amount of methanol (30%, 40% and 50%). The fractions are examined by TLC and the appropriate fractions purified by preparative HPLC to afford the desired purified components.

It has been discovered that BU-3889V A₁ can be converted to BU-3889V D₁ by treatment with 1.5N methanolic hydrogen chloride at about 40°-60° C. for 1 to 4 days, preferably 2 to 3 days. The desired product is isolated by chromatographic techniques similar to those described above.

In a similar manner, BU-3889V A₂ may be converted to BU-3889V D₂ and BU-3889V A₃ to BU-3889V D₃.

BU-3889V A₁ can be converted to BU-3889V A₃ by reduction, e.g. with sodium borohydride at 25°-40° C. Chromatographic techniques are used for isolation and purification of A₃.

In a similar manner, BU-3889V A₂ may be converted to BU-3889V D₂ and BU-3889V A₃ to BU-3889V D₃.

Physical and Chemical Properties of BU-3889V A₁, BU-3889V A₂, BU-3889V A₃ and BU-3889V D₁

BU-3889V A₁, A₂ and A₃ were isolated as a pale-yellow amorphous powder of weakly acidic nature. They were soluble in water, dimethylformamide and dimethyl sulfoxide, slightly soluble in methanol and acetone but practically insoluble in other organic solvents. BU-3889V D₁ was obtained as pale-yellow needles. It was soluble in dimethylformamide and dimethyl sulfoxide but only slightly soluble in water and methanol. Both BU-3889V A₁ and D₁ showed positive reactions to iodine, ferric chloride, Tollen's and 2,4-dinitrophenylhydrazine, but were negative to ninhydrin, Sakaguchi and Ehrlich tests. BU-3889V A₁ was positive to anthrone reagent while BU-3889V D₁ was negative in that test. All BU-3889V components were labile to light. Upon exposing to fluorescent light at room temperature, they decomposed completely in 4 to 5 days. The physicochemical properties of the four components are summarized in Table 5. The UV spectra of the components were quite similar, exhibiting the maxima at around 238 and 302 nm in water or methanol and no shift was observed in acidic or alkaline media. The IR spectra of BU-3889V A₁, A₂, A₃ and D₁ are shown in FIGS. 6 to 9.

The molecular weights of A₁ and D₁ were determined by negative fast-atom bombardment mass spectrometry (JEOL JMSSX 102, matrix: glycerol +thioglycerol). Those of A₂ and A₃ were assigned on the basis of their structural differences from A₁ as revealed by their ¹ H- and ¹³ C-NMR.

The products of the invention show a shift in IR spectra when treated with dilute sodium hydroxide indicating that sodium salts and other metallic salts can be formed. Such salts are within the scope of the invention.

                  TABLE 5A                                                         ______________________________________                                         Physico-chemical properties of BU-3889V A.sub.1 and A.sub.2                             A.sub.1       A.sub.2                                                 ______________________________________                                         Nature:    Pale-yellow powder                                                                             Pale-yellow powder                                  M.P.:      >250° C. >250° C.                                     [α].sub.D.sup.25 :                                                                  +180°    +108°                                                   (c 0.56, H.sub.2 O)                                                                            (c 0.55, H.sub.2 O)                                 Negative:  m/z                                                                            1541 (M - 2H + K).sup.-                                             FAB-MS:  1525 (M - 2H + Na).sup.-,                                                      1563 (M - 3H + K + Na).sup.-                                          Mol. wt.:  1504            1506                                                Elemental: found           found                                               analysis   C 52.20%        C 53.23%                                                       H 5.06          H 5.22                                              UV λ.sub.max.sup.nm (ε):                                        in H.sub.2 O                                                                              238 (84,000)    238 (74,100)                                                   302 (56,300)    302 (59,600)                                        in 0.01N   238 (71,500)    237 (72,700)                                        HCl        304 (49,000)    303 (55,900)                                        in 0.01N   238 (79,300)    237 (76,900)                                        NaOH       302 (53,800)    302 (59,800)                                        IR (KBr):  3420, 1710, 1620                                                                               3410, 1710, 1620                                    cm.sup.-1  1550, 1450, 1150                                                                               1550, 1450, 1140                                               1100-1000       1100-1000                                           TLC, SiO.sub.2 :                                                                          Rf        0.05      0.05                                            (n-BuOH-n-PrOH-CONC.NH.sub.4 OH--H.sub.2 O = 3:3:1:1)                          TLC, RP-18:                                                                               Rf       0.22       0.43                                            (Merck: MeOH-0.022M Phosphate buffer, pH 7.0, 50:50)                           HPLC:      Rt       11.6 min   6.8 min                                         (Capcell pak C18, MeOH-0.05M Sorensen buffer, pH 8.0,                          30-55% gradient)                                                               ______________________________________                                          Capcell pak C18 is a siliconcoated spherical silica gel available from         Shiseido, Japan.                                                               RP-18 is a precoated reversed phase silica gel thin layer plate available      from Merck.                                                              

                  TABLE 5B                                                         ______________________________________                                         Physico-chemical properties of BU-3889V A.sub.3 and D.sub.1                            A.sub.3      D.sub.1                                                   ______________________________________                                         Nature:   Pale-yellow powder                                                                            Pale-yellow needles                                   M.P.:     >250° C.                                                                               >250° C.                                       [α].sub.D.sup.25 :                                                                 +36°    +34°                                                     (c 0.55, H.sub.2 O)                                                                           (c 0.5, Pyridine)                                     Negative:                m/z                                                                            1217 (M - 2H + K).sup.-                               FAB-MS:                  1239                                                                           (M - 3H + K + Na).sup.-,                                                       1201 (M - 2H + Na).sup.-                              Mol. wt.: 1508           1180                                                  Elemental:                                                                               found          found                                                 analysis  C 52.64%       C 52.28%                                                        H 5.30         H 5.42                                                UV λ.sub.max.sup.nm (ε):                                        in H.sub.2 O                                                                             237 (74,200)   235 (66,000)                                                    301 (64,900)   302 (52,500)                                          in 0.01N  237 (62,000)   232 (51,600)                                          HCl       302 (56,300)   306 (46,600)                                          in 0.01N  238 (69,900)   237 (66,000)                                          NaOH      302 (60,600)   301 (52,500)                                          IR (KBr): 3410, 1710, 1620                                                                              3430, 1710, 1620                                      cm.sup.-1 1550, 1440, 1150                                                                              1550, 1455, 1380                                                1100-1000      1080, 1000, 800                                       TLC, SiO.sub.2 :                                                                         Rf        0.05     0.34                                              (n-BuOH-n-PrOH-CONC.NH.sub.4 OH--H.sub.2 O = 3:3:1:1)                          TLC, RP-18:                                                                              Rf       0.55      0.10                                              (Merck: MeOH-0.022M Phosphate buffer, pH 7.0, 50:50)                           HPLC:     Rt       4.2 min   17.9 min                                          (Capcell pak C18, MeOH-0.05M Sorensen buffer, pH 8.0,                          30-55% gradient)                                                               ______________________________________                                          Capcell pak C18 is a siliconcoated spherical silica gel available from         Shiseido, Japan.                                                         

RP-18 is a precoated reversed phase silica gel thin layer plate available from Merck.

Physico-chemical Properties of Bu-3889V D₂ and BU-3889V D₃

BU-3889V D₂ an D₃ components had the same solubility, color test and light stability properties as component D₁. They showed physico-chemical properties similar to each other and also to those of BU-3889V D₁ (Table 6). The molecular weights were suggested to be 1182 for BU-3889V D₂ and 1184 for BU-3889V D₃ by negative FAB-MS. The IR spectra of BU-3889V D₂ and D₃ are shown in FIGS. 16 and 17 and their ¹ H-NMR spectra are shown in FIGS. 18 and 19 respectively. Table 7 shows the ¹ H and ¹³ C-NMR data of BU-3889V D₃.

                  TABLE 6                                                          ______________________________________                                         Physico-chemical properties of                                                 BU-3889V D.sub.2 and D.sub.3                                                           BU-3889V D.sub.2                                                                            BU-3889V D.sub.3                                          ______________________________________                                         Nature:   Pale-yellow powder                                                                            Pale-yellow powder                                    M.P.:     >250° C.                                                                               >250° C.                                       [α].sub.D.sup.26 :                                                                 -13°    -17°                                                     (C 0.4, pyridine)                                                                             (C 0.4, pyridine)                                     Negative  m/z 1219       m/z                                                   FAB-MS:   (M - 2H + K).sup.-                                                                            1205 (M - 2H + Na).sup.-                                                       1221 (M - 2H + K).sup.-                               Mol. wt.: 1182           1184                                                  Elemental:                                                                               Found          Found                                                 analysis  C 52.47%       C 58.54%                                                        H 4.97         H 5.80                                                UV λ.sub.max.sup.nm (ε):                                        in H.sub.2 O                                                                             237 (62,200)   237 (54,200)                                                    301 (50,400)   300 (47,200)                                          in 0.01N HCl                                                                             237 (52,000)   237 (41,000)                                                    302 (42,900)   301 (37,900)                                          in 0.01N NaOH                                                                            237 (65,400)   237 (57,100)                                                    301 (49,900)   300 (45,200)                                          IR (KBr) cm.sup.-1:                                                                      3420, 1710, 1630                                                                              3420, 1720, 1620                                                1550, 1450, 1080,                                                                             1540, 1455, 1080,                                               1000           1000                                                  TLC, SiO.sub.2 :                                                                         Rf       0.30      0.28                                              (n-BuOH-n-PrOH-conc. NH.sub.4 OH--H.sub.2 O = 3:3:1:1)                         TLC, RP-18:                                                                              Rf       0.14      0.18                                              (Merck: MeOH-0.022M phosphate buffer, pH 7.02, 50:50)                          HPLC:     Rt       12.52 min 9.55 min                                          (Capcell pak C18, MeOH-0.05M Sorensen buffer, pH 8.0, 30-55%                   gradient)                                                                      ______________________________________                                    

                  TABLE 7                                                          ______________________________________                                         .sup.1 H and .sup.13 C-NMR data of BU-3889V D.sub.3                            .sup.1 H-NMR data   .sup.13 C-NMR data                                         (DMSO-d.sub.6)      (DMSO-d.sub.6)                                             ______________________________________                                         δ                                                                               7.40    (1H, d, J=15.4) δ                                                                            197.3                                                                               s                                      6.79       (1H, d, j=15.4)   193.9  s                                          6.75       (1H, br-d, j=8.1) 193.7  s                                          6.10       (2H, m)           182.3  s                                          5.67       (1H, s)           174.7  s                                          5.21       (1H, s)           173.9  s                                          *4.81      (1H, m)           146.3  d                                          *4.71      (1H, m)           145.6  d                                          *4.51      (1H, s)           141.4  s                                          ca. 4.0    (4H, m)           139.4  s                                          2.50       (1H, m)           133.7  d                                          2.39       (2H, m)           133.3  s                                          1.71       (3H, s)           125.9  d                                          1.70       (1H, m)           125.7  d                                          1.50       (1H, m)           125.1  d                                          1.40       (1H, m)           124.3  d                                          1.23       (3H, s)           96.8   s                                          1.11       (3H, d, j=7.3)    94.1   s                                          1.00       (3H, d, j=6.8)    84.8   s                                          0.96       (3H, s)           84.4   s                                                                       63.6   t                                                                       62.4   t                                                                       43.9   s                                                                       43.6   s                                                                       36.1   t                                                                       34.5   t                                                                       27.6   d                                                                       27.3   d                                                                       26.7   q                                                                       21.7   q                                                                       20.5   q                                                                       19.1   q                                                                       12.2   q                                          ______________________________________                                          *exchangeable with D.sub.2 O                                             

Antiviral Activity of BU-3889V A₁, BU-3889V A₂, BU-3889V A₃ and BU-3889V D₁ 1. Antiviral activity against herpes simplex virus type 1 and influenza virus A

In vitro antiviral activity of BU-3889V was assessed using the herpes simplex virus type 1 (HSV-1)-Vero cell and influenza virus A-Madin Darby canine kidney (MDCK) cell systems by dye-uptake assay method (Antiviral Research 3 223-234, 1986). A 200 μl aliquot of cell suspension containing 2×10⁴ cells was inoculated to each well of 96-well microplates and cultured at 37° C. for 48-72 hours under humidified 5% CO₂ -95% air. Thereafter, the growth medium was replaced by 250 μl of a fresh medium containing a test compound, to which a 50 μl medium containing approximately 10×TCID₅₀ of virus was added. After 72 hours incubation, the degree of inhibition of viral-induced cytopathic effect and drug-induced cytotoxicity were determined. ID₅₀ was expressed as the concentration showing 50% inhibition of cytopathic effect of control and TD₅₀ was the concentration exhibiting 50% cytotoxicity against Vero or MDCK cell without viral infection. Acyclovir and ribavirin were used as the reference compounds of anti-HSV activity and anti-influenza virus A activity, respectively. The results are shown in Table 8. BU-3889V A₁, A₂ and A₃ exhibited antiviral activity against HSV with ID₅₀ values of 11 μg/ml and BU-3889V D₁ exhibited antiviral activity against influenza virus type A with an ID₅₀ value of 6.8 μg/ml.

                  TABLE 8                                                          ______________________________________                                         Antiviral activity against herpes simplex virus                                type 1 and influenza virus A                                                          HSV-Vero cell                                                                              Influenza virus-MDCK cell                                          ID.sub.50                                                                             TD.sub.50                                                                               ID.sub.50  TD.sub.50                                           (μg/ml)                                                                            (μg/ml)                                                                              (μg/ml) (μg/ml)                                   ______________________________________                                         BU-3889V A.sub.1                                                                        11       >400     150      250                                        BU-3889V A.sub.2                                                                        11       >200     >150     150                                        BU-3889V A.sub.3                                                                        11       >200     88       180                                        BU-3889V D.sub.1                                                                        92       >200     6.8      160                                        Acyclovir                                                                               0.09     >100                                                         Ribavirin                  15       >200                                       ______________________________________                                          2. Anti-HIV activity

Anti-HIV activity was evaluated using the human T-lymphotropic virus type III B (HTLV-IIIB) and HTLV-type I carrying, MT-4 cells. The number of viable MT-4 cells infected with HIV at a multiplicity of infection of 0.002, decreased during the cultivation and almost all cells died within 6 days after infection as determined by a trypan blue dye exclusion method (Antimicrob. Agents and Chemother. 30 933-37, 1986).

Cell damage induced by HIV was significantly inhibited by BU-3889V A₁ and D₁ at concentration higher than 25 μg/ml (FIG. 11), and weak cytotoxicity was observed at 100 μg/ml of BU-3889V A₁ and D₁.

Expression of HIV antigen was examined by immunofluorescence. When MT-4 cells were infected with HIV, viral antigen positive cells increased with incubation time and all the cells became positive on day 6 after infection. HIV antigen positive cells were significantly suppressed when HIV-infected MT-4 cells were cultured in the presence of BU-3889V A₁ and D₁, and positive cells were only less than 1% at the concentration higher than 50 μg/ml of the compounds (FIG. 10).

Inhibitory activity of BU-3889V A₁ and D₁ on reverse transcriptase (RTase) derived from avian myeloblastosis virus (AMV) was examined. Concentrations higher than 3 μg/ml of BU-3889V A₁ and D₁ inhibited 1 unit of AMV RTase activity more than 95% (Table 9).

                  TABLE 9                                                          ______________________________________                                         Effect of BU-3889V A.sub.1 and D.sub.1 on the AMV reverse                      transcriptase activity                                                         Compound                                                                       Concentration                                                                  (μg/ml)    BU-3889V A.sub.1                                                                           BU-3889V D.sub.1                                     ______________________________________                                         100           159 ± 14.sup.a                                                                          185 ± 66                                                        .sup. (99.7).sup.b                                                                         (99.6)                                               50            235 ± 73 198 ± 80                                                        (99.5)      (99.6)                                               25            621 ± 402                                                                               134 ± 55                                                        (98.8)      (99.8)                                               12.5          920 ± 271                                                                               116 ± 14                                                        (98.2)      (99.8)                                               6             976 ± 145                                                                               287 ± 98                                                        (98.1)      (99.4)                                               3             1,584 ± 1,292                                                                           785 ± 69                                                        (96.9)      (98.5)                                               0             51,494 ± 1,865                                                (Control)                                                                      ______________________________________                                          .sup.a count (cpm)                                                             .sup.b % inhibition                                                      

Antiviral Activity of BU-3889V A₃, D₂ and D₃ against herpes simplex virus type 1 and influenza virus A

The in vitro antiviral activity of BU-3889V A₃, D₂ and D₃ was assessed using the herpes simplex virus type 1 (HSV-1 )-Vero cell and influenza virus A-Madin Darby Canine kidney (MDCK) cell systems by the dye-uptake assay (Antiviral Research 3, p. 223-234, 1986). A 200 μl aliquot of cell suspension containing 2×10⁴ cells was inoculated to each well of 96- well microplates and cultured at 37° C. for 48-72 hours under humidified 5% CO₂ -95% air. Thereafter, the growth medium was replaced by 250 μl of a fresh medium containing a test compound, to which a 50 μ1 medium containing approximately 10×TCID₅₀ of virus was added. After 72 hours incubation, the degree of inhibition of viral-induced cytopathic effect and drug-induced cytotoxicity were determined. ID₅₀ was expressed as the concentration showing 50% inhibition of cytopathic effect of control and TD₅₀ was the concentration exhibiting 50% cytotoxicity against Vero or MDCK cells without viral infection. Acyclovir and ribavirin were used as the reference compounds of anti-HSV activity and anti-influenza virus A activity, respectively. The results are shown in Table 10.

                  TABLE 10                                                         ______________________________________                                         Antiviral activity against herpes simplex virus                                type I and influenza virus A                                                          HSV-Vero cell                                                                              Influenza virus-MDCK cell                                          ID.sub.50                                                                             TD.sub.50                                                                               ID.sub.50  TD.sub.50                                           (μg/ml)                                                                            (μg/ml)                                                                              (μg/ml) (μg/ml)                                   ______________________________________                                         BU-3889V D.sub.1                                                                        35       >100     9.9        68                                       BU-3889V D.sub.3                                                                        20       >100     24       >100                                       BU-3889V A.sub.3                                                                        6.3      >100     41       >100                                       Acyclovir                                                                               0.09     >100                                                         Ribavirin                  9.5      >100                                       ______________________________________                                    

Anti-HIV activity of BU-3889V A₁, A₂ and A₃

The in vitro anti-HIV activity of BU-3889V A₁, A₂ and A₃ was evaluated in the p24gag antigen capture assay using CEM-F cells. AZT was included as a reference compound. The methodology used in this assay is described below:

Methodology Cells and Virus

The cells and the virus were grown in LAV/CEM medium. The medium consists of RPMI 1640, supplemented with 1% L-glutamine, 100 U/ml of Penicillin, 100 μg/ml Streptomycin, 2 μg/ml Polybrene and 10% heat-inactivated fetal bovine serum (HyClone Labs). CEM cells were originally derived from acute human lymphoblastic leukemia and represent an established T lymphoblastoid cell line. The LAV/BRU of human immunodeficiency virus (HIV) was obtained from Dr. L. Montagnier, Institute Pasteur, Paris, France. The virus was adapted to CEM cells, and infectious virus stocks were stored as cell-free supernatant fluids in 1 ml aliquots in liquid nitrogen. The titer of the stock was determined by an end point titration method using CEM cells in 96-well microtiter plates. The titration was done with ten replicates for each point, and the 50% tissue culture infective dose (TCID₅₀) was calculated using the method of Reed and Muench (Amer. J. Hygiene, 27/3 (1938) 493-497).

Inhibition of HIV Replication

The CEM cells (1.5×10⁵ cells/ml) were placed in 96-well plates and incubated with virus for 45 minutes. After 45 minutes each compound was added in quadruplicate. At the end of the day, six supernatants were tested for presence of viral core protein p24gag in an antigen capture ELISA (Genetic Systems Company). The OD readings (absorbance at 450/630 nm) fall into three categories: Experimentals=values from wells containing cells, viral inoculum and drug; Controls=values from wells with cells and virus (100%); and Background=values from wells with viral inoculum alone. The background value was subtracted from all the experimental ODs. The antiviral effect is expressed as infective or effective dose 50 (ID₅₀ or ED₅₀) and represents the amount of drug necessary to reduce the viral replication by 50% as measured through p24gag binding.

Analysis of Cytoxicity

The toxicities of the drugs were tested against uninfected CEM cells. The CEM cells were plated as described above, and culture for five days in the presence or absence of drugs. On day five 1 μCi/well of ³ H-thymidine was added, and cells were harvested 3 hours later. The results are expressed as toxic dose 50 (TD₅₀) and represent the amount of drug necessary to reduce the cell proliferation by 50% as measured through thymidine incorporation. The results of the assay are shown in Table 11.

                  TABLE 11                                                         ______________________________________                                         Anti-HIV activity using p24gag antigen capture assay                           Compound        μg ED.sub.50                                                                         μg TD.sub.50                                       ______________________________________                                         BU-3889V A.sub.1                                                                               3.2      >100                                                  BU-3889V A.sub.2                                                                               2.5      >100                                                  BU-3889V A.sub.3                                                                               6.8      95                                                    AZT              0.055   4.2                                                   ______________________________________                                    

Anti-HIV activity of BU-3889V D₂ and D₃

The BU-3889V components were evaluated for activity against human immunodeficiency virus (LAV_(BRU) strain obtained from Luc Montagnier, Institut Pasteur, Paris, France) in CEM-SS cells (P.L. Nara et al. in AIDS Res. Human Retroviruses, 1987, 3, 283-302) using the XTT assay described by D. S. Weislow, et al. in J. Natl. Cancer Institut., 1989, 81, 577-586. CEM-SS cells were obtained from Owen Weislow at the National Cancer Institute.

The antiviral effect is expressed as the concentration of compound which increases the number of viable cells in infected cultures to 50% that of the untreated, uninfected control cultures (ED₅₀) The cellular toxicity is expressed as the concentration of compound which reduces the number of viable cells to 50% that of the untreated control (TD₅₀). Table 12 shows the results of this assay.

                  TABLE 12                                                         ______________________________________                                         Anti-HIV activity of BU-3889V components in CEM-                               SS cells evaluated by XTT assay six days post infection                        Compound      μg/ml ED.sub.50                                                                        μg/ml TD.sub.50                                    ______________________________________                                         BU-3889V A.sub.1                                                                             20         300                                                   BU-3889V A.sub.2                                                                             10         200                                                   BU-3889V A.sub.3                                                                             25         600                                                   BU-3889V D.sub.1                                                                             20         >500                                                  BU-3889V D.sub.2                                                                             20         >500                                                  BU-3889V D.sub.3                                                                             10         100                                                   AZT           0.005      >500                                                  ______________________________________                                    

Methods of Use and Pharmaceutical Compositions

The antiviral antibiotic complex, BU-3889V and its components A₁, A₂, A₃, D₁, D₂ and D₃ according to the present invention and pharmaceutical compositions thereof are useful to inhibit the growth of viruses, including the herpes simplex and influenza viruses. These antiviral effects are demonstrated and described above. In addition, BU-3889V A₁, A₂, A₃, D₁, D₂ and D₃ are useful in the inhibition of HIV virus.

In general, the antibiotics of the invention may be administered orally or parenterally in pure solid form, in dilute solutions or suspensions or in concentrates and prepared for unit dose or multi-dose presentation. When administered parenterally, by intravenous or intramuscular or subcutaneous injection, or when administered orally, the dosage administration will be dependent on the age and weight of the mammalian species being treated, the route of administration, and the type and severity of the infectious condition being treated and other factors readily evaluated by the physician or veterinarian in attendance.

In respect to pharmaceutical compositions containing the antibiotics herein, carrier and other ingredients should be such as not to diminish the therapeutic effects of the antibiotic. Suitable dosage forms for oral use are tablets, dispersible powders, granules, capsules, syrups and elixirs. Examples of parenteral forms are solutions, suspensions, dispersions, emulsions, and the like. The compositions for oral use may contain one or more conventional adjuvants, such as sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a composition of suitable pharmaceutical elegance. Tablets may contain the active ingredient in admixture with conventional pharmaceutically acceptable excipients including inert diluents such as calcium carbonate, sodium carbonate, lactose and talc; granulating and disintegrating agents such as starch and alginic acid; binding agents such as starch, gelatin and acacia and lubricating agents such as magnesium stearate, stearic acid and talc. The tablets may be uncoated or coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. Similarly, suspensions, syrups, and elixirs may contain the active ingredients in admixture with any of the conventional excipients utilized for the preparation of such compositions such as suspending agents (e.g., methylcellulose,. tragacanth, and sodium alginate), wetting agents (e.g., lecithin, polyoxyethylene stearate) and preservatives such as ethyl p-hydroxybenzoate. Capsules may contain the active ingredient alone or admixed with an inert solid diluent such as calcium carbonate, calcium phosphate and kaolin. The injectable compositions are formulated as shown in the art and may contain appropriate dispersing or wetting agents and suspending agents identical or similar to those mentioned above.

The daily dosage for adult human treatment will preferably range from about 100 mg to about 1,000 mg of the selected therapeutic agent for a 70 kg adult, depending on the nature of the infection and the frequency and route of administration inter alia. It will be appreciated that in some instances, e.g. in the treatment of neonates, infants and juveniles, smaller dosages than adult dosages may be desired.

The pharmaceutical compositions of this invention thus will generally comprise a growth inhibitory amount (i.e. an amount effective to inhibit the growth of the virus causing the condition of infection to be treated) of BU-3889V or its components in a suitable pharmaceutically acceptable carrier such as water or alcohols which may contain fillers, stabilizers, wetting agents, emulsifying agents and dispersing agents to name but a few conventional carriers, adjuvant and excipients which may be employed.

The following examples are given by way of illustration only and are not to be considered limitations of this invention, many apparent variations of which are possible without departing from the spirit and scope thereof.

EXAMPLE 1

A piece of the mature slant culture of Amycolatopsis orientalis ATCC-53884 was inoculated into a 500-ml Erlenmeyer flask containing 100 ml of a seed medium comprising soluble starch (Nichiden Kagaku) 0.5%, glucose 0.5%, fish meat extract (Mikuni) 0.1%, NZ-case (Sheffield) 0.2%, NaCl 0.2% and CaCO₃ 0.1% (pH 7.0). The seed culture was incubated at 32° C. for 4 days on a rotary shaker (200 rpm). A five-milliliter portion of the above seed culture was transferred into a 500-ml Erlenmeyer flask containing 100 ml of a fermentation medium composed of soluble starch 2%, beet molasses (Nihon Tensai Seito) 1% and CaCO₃ 0.5% (pH 7.0). Fermentation was carried out at 28° C. for 7 days on a rotary shaker (200 rpm). The antibiotic production in the fermentation broth was determined by the dye-uptake assay method using herpes simplex virus type 1.

The fermentation broth showed the antiviral activity at 12× dilution during 4 through 7 day's fermentation. Large scale fermentation of ATCC-53884 was carried out in a tank fermentor (200 L). A two-liter portion of the seed culture prepared by flask fermentation was transferred into a 200-liter tank fermentor containing 120 liters of the production medium having the same composition as the medium which was used in flask fermentation. The tank fermentation was carried out at 32° C. with agitation of 250 rpm and aeration rate of 120 liters per minute.

The fermentation broth (210 L, 50-100 mcg/ml) was centrifuged using a Sharples centrifuge. The clarified supernatant (200 L) was adjusted to pH 7.0 with 6N HCl, stirred vigorously with Diaion HP-20 resin (20 L) for one hour and filtered. The resin was washed with water (30 L) and then 20% aqueous methanol (30 L). Upon monitoring by dye-uptake assay with herpes simplex virus type 1 the activity was eluted with 80% aqueous acetone (pH 8.0, 20 L). Active effluents were combined and concentrated in vacuo to an aqueous solution (4.5 L) which was, after being adjusted to pH 7.0, applied to a column of Diaion HP-20 (2.4 L). The column was developed with water and 80% aqueous methanol (9 L), successively. The bioactive methanolic eluate was evaporated under reduced pressure to an aqueous solution (3.5 L) which was washed with ethyl acetate (1.5 L). The aqueous layer was taken up and concentrated to afford a crude solid of BU-3889V (31.6 g).

All operations described hereafter were conducted in a dark room.

A part of the crude solid obtained above (23.8 g) was mixed with silica gel (130 ml) and loaded on the top of a silica gel column (Wakogel C-200, 350 ml). The column was developed stepwisely with n--BuOH--n--PrOH--conc.NH₄ OH--H₂ O mixture (5:5:1:1, 2L, fr. Nos. 1--20 and 3:3:1:1, 4 L, fr. Nos. 21-66). Eluted fractions (100 ml) were monitored by the antiviral assay and TLC (SiO₂ ; n--BuOH--n--PrOH--conc.NH₄ OH--H₂ O, 3:3:1:1; UV and H₂ SO₄ detection). Fractions Nos. 8 and 9 were combined and concentrated in vacuo to yield a crude solid of BU-3889V D₁ (410 mg). The second active pools, fractions Nos. 31 to 41, were worked up by the same way to afford a mixture (6.35 g) which was found to contain three components BU-3889V A₁, A₂ and A₃ by HPLC. This solid (390 mg) was dissolved in 4 ml of 0.022M phosphate buffer (pH 7.0) and subjected to a reversed C₁₈ column chromatography (YMC-ODS, AM type, Yamamura Chem. Lab. Co., Ltd., 800 ml). The column was developed with the 0.022M phosphate buffer solution containing an increasing amount of methanol (25%, 28%, 30% and 35%) and the eluate was examined by TLC (RP-18, Merck; MeOH-0.022M phosphate buffer, pH 7.0, 50:50). The first active fractions containing component A₃ were collected and concentrated to a small volume (30 ml) which was applied to a column of Diaion HP-20 (50 ml). After washing with water, the column was eluted with 80% aqueous methanol to afford a pure solid of BU-3889V A₃ (70 mg, 97% purity by HPLC). The second and third active eluates were worked up in a similar fashion to yield purified solids of BU-3889V A₂ (87 mg, 97% purity) and A₁ (54 mg, 91% purity) respectively. Further purification of BU-3889V A₁ (52 mg) was carried out by preparative HPLC (column; Capcell pak C₁₈, Shiseido, 30×250 mm, mobile phase; MeOH-0.05M Sorensen buffer, pH 8.0, 30-55% linear gradient, detection; UV 254 nm, flow rate; 5 ml/min). the peak cuts were collected and concentrated to a small volume (35 ml) which was adjusted to pH 7.0 and applied to a column of Diaion HP-20 (80 ml). After washing with water, the column was eluted with 80% aqueous methanol to afford pure solid BU-3889V A₁ (39 mg, 98.7% purity).

Purification of BU-3889V D₁

The crude solid of component D₁ (410 mg) obtained as described above was dissolved in 4 ml of 50% aqueous t-BuOH and applied to a YMC-ODS column (AM type, 800 ml). The column was developed successively with mixture of MeOH-0.022M phosphate buffer, pH 7.0 (20:80, 30:70, 40:60 and 50:50). The fractions (20 ml) were examined by TLC (SiO₂ : n--BuOH--n--PrOH--conc.NH₄ OH--H₂ O, 3:3:1:1) and the appropriate fractions were concentrated to give semi-pure solid BU-3889V D₁ (18 mg, 45% purity). The solid was further purified by preparative HPLC under the same conditions as used for that of BU-3889V A₁ to afford pure solid BU-3889V D₁ (3.6 mg, 96% purity).

EXAMPLE 2

Preparation of BU-3889V D₁ from BU-3889V A₁

A solution of BU-3889V A₁ (870 mg, 83% purity) in 40 ml of 1.5N methanolic hydrogen chloride was stirred at 50° C. for 2 days. The reaction mixture was neutralized with Amberlite IR45(OH³¹) and concentrated in vacuo. The residue was stirred vigorously with a mixture of n-butanol and water (200 ml each). The n-BuOH layer was taken up and evaporated to dryness. The residue (690 mg) was purified by column chromatography on YMC-ODS (AM-type, 800 ml) to give a purer sample of solid D₁ (390 mg, 80% purity). This (80 mg) was finally purified by preparative HPLC to isolate a pure sample of BU-3889V D₁ (30 mg) which was identical with the natural product in all respects. This sample was crystallized from a mixture of MeOH-EtOAc to deposit pale-yellow needles of homogeneous BU-3889V D₁ (14 mg).

The aqueous layer of the above hydrolyzate was concentrated to a small volume which was charged on a column of Sephadex LH-20 (250 ml). Upon developing with 50% methanol, the anthrone-positive fractions were combined and evaporated to yield a white amorphous solid (60 mg). This product was identified as methyl D-galactoside by a direct comparison with an authentic sample and by optical rotational value [(α)²⁵ D+72°, c 3.0, H₂ O].

EXAMPLE 3 Preparation of BU-3889V A₃ from BU-3889V A₁

To an aqueous ethanolic solution (1:1, 100 ml) of BU-3889V A₁ (0.96 g) was added sodium borohydride (1.1 g) with stirring at room temperature. After 3 minutes, the reaction mixture was poured into ice water and the aqueous solution adjusted to pH 7.0 with 6N HCl. The solution was applied on a column of Diaion HP-20 (320 ml) which was washed with water and eluted with 80% aqueous acetone. The eluate containing the product was concentrated in vacuo to give 1.18 g of yellow powder. A portion of the powder (390 mg) was purified by reversed phase column chromatography (YMC-ODS, 680 ml) with stepwise elution of 20-40% methanol in 0.017M Sorensen buffer (pH 7.0) to yield a pure sample (82 mg). It was identical with BU-3889V A₃ obtained from the fermentation products in both spectral data and HPLC.

EXAMPLE 4 Isolation of BU-3889V D₂ and D₃

A portion of the crude solid of BU-3889V D₁ (1.47 g) obtained by the general procedure of Example 1 was dissolved in 8 ml of 50% aqueous t-butanol and subjected to a reversed-phase C₁₈ column chromatography (YMC-ODS, AM type, Yamamura Chem. Lab. Co., Ltd., 600 ml). The column was developed with a 0.022M phosphate buffer solution containing an increasing amount of methanol (30%, 40% and 50%) and the eluate was examined by TLC (RP-18, Merck; MeOH-0.022M phosphate buffer, pH 7.0=50:50 v/v). The first active fractions (Rf 0.18) were pooled, concentrated in vacuo to a small volume (40 ml) which was applied to a column of Diaion HP-20 (100 ml). After washing with water, the column was eluted with 80% aqueous methanol to afford a semi-pure solid of BU-3889V D₃ (260 mg, 53% purity by HPLC). The second (Rf 0.14) and third (Rf 0.10) active fractions were worked up by the same way to yield solids of BU-3889V D₂ (154 mg, 48% purity) and BU-3889V D₁ (97 mg, 33% purity), respectively. These materials were further purified by preparative HPLC (Column: Capcell pak C₁₈, Shiseido, 30×250 mm, mobile phase: MeOH-0.05M Sorensen buffer, pH 8, 30-55% linear gradient, detection: UV 254nm, flow rate: 15/ml/min). The peak cuts containing pure D₃ and those containing pure D₃ were collected and desalted by a column of Diaion HP-20 to afford reasonably pure solids of BU-3889V D₂ (32 mg, 92% purity) and BU-3889V D₃ (77 mg, 91% purity) respectively.

EXAMPLE 5 Chemical derivatization of BU-3889V D₂ and D₃ A. Conversion of BU-3889V A₂ →D₂

BU-3889V A₂ (475 mg, 80% purity) dissolved in 40 ml of 1.5 N methanolic hydrogen chloride was stirred at 50° C. for 24 hours. The mixture was neutralized by 6N NaOH and concentrated in vacuo. The concentrate (30 ml) was applied to a column of Diaion HP-20 (100 ml) which was washed with water and eluted with 80% aqueous methanol (250 ml). The active eluate was evaporated to give a light-brown powder (388 mg). This solid was further purifed by column chromatography of YMC-ODS (AM type, 800 ml), followed by desalting with Diaion HP-20 to afford a pure sample (173 mg), which was identical in all respects with BU-3889V D₂ obtained from the fermentation broth.

B. Conversion of BU-3889V A₃ →D₃

BU-3889V A₃ (600 mg, 82%) was hydrolyzed in 1.5N methanolic hydrogen chloride at 50° C. for 24 hours. The reaction solution was worked up as indicated above in Step (A) to afford pure BU-3889V D₃ (81 mg). The material was identical with the fermentation-obtained product obtained in Example 4. 

What is claimed is:
 1. The antiviral antibiotic designated BU-3889V A₁ which, when purified, is in the form of a pale yellow solid having a melting point above 250° C.; a specific optical rotation [α]²⁵ of +180 degrees (C 0.56, H₂ O); a molecular weight of 1504; an R_(f) value in thin layer chromatographic analysis using silica gel of 0.05 with n--BuOH--n--PrOH--conc. NH₄ OH--H₂ O, 3:3:1:1 and of 0.22 using reversed phase silica gel with MeOH-0.022M phosphate buffer, pH 7.0, 50:50; is soluble in water, dimethylformamide and dimethyl sulfoxide and slightly soluble in methanol and acetone; gives a positive response to anthrone reagent, iodine, ferric chloride, Tollen's reagent and 2,4-dinitrophenylhydrazine, and a negative response in the ninhydrin, Sakaguchi and Ehrilich's tests; is labile to light; gives an infrared spectrum substantially as shown in FIG. 6; gives a high performance liquid chromatographic spectrum substantially as shown in FIG. 2; gives the ¹³ C-NMR nuclear magnetic resonance spectrum substantially as shown in Table 3; gives ¹ H-NMR spectrum substantially as shown in FIG. 12 and is effective in inhibiting the growth of viruses.
 2. The antiviral antibiotic designated BU-3889V A₂ which, when purified, is in the form of a pale yellow solid having a melting point above 250° C.; a specific optical rotation [α]²⁵ of +108 degrees (C 0.55, H₂ O); a molecular weight of 1506; an R₅ value in thin layer chromatographic analysis using silica gel of 0.05 with n--BuOH--n--PrOH--conc. NH₄ OH--H₂ O, 3:3:1:1 and of 0.43 using reversed phase silica gel with MeOH-0.022M phosphate buffer, pH 7.0, 50:50; is soluble in water, dimethylformamide and dimethyl sulfoxide and slightly soluble in methanol and acetone; gives a positive response to anthrone reagent, iodine, ferric chloride, Tollen's reagent and 2,4-dinitrophenylhydrazine, and a negative response in the ninhydrin, Sakaguch and Ehrlich's tests; which is labile to light; gives an infrared spectrum substantially as shown in FIG. 7; gives a high performance liquid chromatographic spectrum substantially as shown in FIG. 3; and is effective in inhibiting the growth of viruses.
 3. The antiviral antibiotic designated BU-3889V A₃ which, when purified, is in the form of a pale yellow solid having a melting point above 250° C.; a specific optical rotation [α]²⁵ of +36 degrees (C 0.55, H₂ O); a molecular weight of 1508; an R₅ value in thin layer chromatographic analysis using silica gel of 0.05 with n--BuOH--n--PrOH--conc. NH₄ OH--H₂ O, 3:3:1:1 and of 0.55 using reversed phase silica gel with MeOH-0.022M phosphate buffer, pH 7.0, 50:50; is soluble in water, dimethylformamide and dimethyl sulfoxide and slightly soluble in methanol and acetone; gives a positive response to anthrone reagent, iodine, ferric chloride, Tollen's reagent and 2,4-dinitrophenylhydrazine, and a negative response in the ninhydrin, Sakaguchi and Ehrlich's tests; which is labile to light; gives an infrared spectrum substantially as shown in FIG. 8; gives a high performance liquid chromatographic spectrum substantially as shown in FIG. 4; gives the ¹ H nuclear magnetic resonance spectrum substantially as shown in FIG. 13; and is effective in inhibiting the growth of viruses.
 4. The antiviral antibiotic designated BU-3889V D₁ which, when purified, is in the form of a pale yellow solid having a melting point above 250° C.; a specific optical rotation [α]²⁵ of +34 degrees (C 0.5, pyridine); a molecular weight of 1180; an R_(f) value in thin layer chromatographic analysis using silica gel of 0.34 with n--BuOH--n--PrOH--conc. NH₄ OH--H₂ O, 3:3:1:1 and of 0.10 using silica gel with MeOH-0.022M phosphate buffer, pH 7.0, 50:50; is soluble in dimethylformamide and dimethyl sulfoxide and slightly soluble in methanol and acetone; gives a positive response to iodine, ferric chloride, Tollen's reagent and 2,4-dinitrophenylhydrazine, and a negative response in the anthrone, ninhydrin, Sakaguchi and Ehrlich's tests; which is labile to light; gives an infrared spectrum substantially as shown in FIG. 9; gives a high pressure liquid chromatographic spectrum substantially as shown in FIG. 5; gives the ¹³ C-nuclear magnetic resonance substantially as shown in Table 3; gives ¹ H-NMR substantially as shown in FIG. 14 and is effective in inhibiting the growth of viruses.
 5. The antiviral antibiotic designated BU-3889V D₂ which, when purified, is in the form of a pale yellow amorphous powder having a melting point above 250° C.; a specific optical rotation of [α]²⁶ _(D) of -13° (C 0.4, pyridine); a molecular weight of 1182 as determined by FAB-MS; an R₅ value in thin layer chromatographic analysis using silica gel of 0.30 with n--BuOH--n--PrOH--conc. NH₄ OH--H₂ O, 3:3:1:1 and of 0.14 using reversed phase silica gel with MeOH-0.022 M phosphate buffer, pH 7.0, 50:50 v/v; is soluble in dimethylformamide and dimethyl sulfoxide and slightly soluble in methanol and acetone; gives a positive response to iodine, ferric chloride, Tollen's reagent and 2,4-dinitrophenylhydrazine and a negative response in the anthrone, ninhydrin, Sakaguchi and Ehrlich's tests; is labile to light; gives an infrared spectrum substantially as shown in FIG. 16; gives a high performance liquid chromatographic spectrum substantially as shown in FIG. 20; gives a ¹ H-NMR spectrum substantially as shown in FIG. 18; exhibits the following UV absorption maxima:

    ______________________________________                                         UV λ.sub.max.sup.nm (ε):                                        ______________________________________                                         in H.sub.2 O    237 (62,200)                                                                   301 (50,400)                                                   in 0.01N HCl    237 (52,000)                                                                   302 (42,900)                                                   in 0.01N NaOH   237 (65,400)                                                                    301 (49,900);                                                 ______________________________________                                    

and is effective in inhibiting the growth of herpes simplex virus type 1 and influenza virus A.
 6. The antiviral antibiotic designated BU-3889V D₃ which, when purified, is in the form of a pale yellow amorphous powder having a melting point above 250° C.; a specific optical rotation [α]²⁶ _(D) of -17° (C 0.4, pyridine); a molecular weight of 1184 as determined by FAB-MS; an R_(f) value in thin layer chromatographic analysis using silica gel of 0.28 with n--BuOH--n--PrOH--conc NH₄ OH--H₂ O, 3:31:1, and of 0.18 using reversed phase silica gel with MeOH-0.022M phosphate buffer, pH 7.0, 50:50 v/v; is soluble in dimethylformamide and dimethyl sulfoxide and slightly soluble in methanol and acetone; gives a positive response to iodine, ferric chloride, Tollen's reagent and 2,4-dinitrophenylhydrazine, and a negative response in the ninhydrin, Sakaguchi and Ehrlich's tests; is anthrone labile to light; gives an infrared spectrum substantially as shown in FIG. 17; gives a high performance liquid chromatographic spectrum substantially as shown in FIG. 20; gives a ¹ H-NMR spectrum substantially as shown in FIG. 19; exhibits the following UV absorption maxima:

    ______________________________________                                         UV λ.sub.max.sup.nm (ε):                                        ______________________________________                                         in H.sub.2 O    237 (54,200)                                                                   300 (47,200)                                                   in 0.01N HCl    237 (41,000)                                                                   301 (37,900)                                                   in 0.01N NaOH   237 (57,100)                                                                    300 (45,200);                                                 ______________________________________                                    

gives a ¹³ C-NMR spectrum which exhibits the signals shown in Table 7; and is effective in inhibiting the growth of herpes simplex virus type 1 and influenza virus A.
 7. The antiviral antibiotic complex designated BU-3889V produced by aerobic fermentation of a BU-3889V producing strain of Amycolatopsis orientalis ATCC-53884 under submerged aerobic conditions in a growth medium containing a source of assimilable nitrogen and carbon and containing the antiviral antibiotics designated BU-3889V A₁, BU-3889V A₂, BU-3889V A₃ and BU-3889V D₁, BU-3889V D₂ and BU-3889V D₃.
 8. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic BU-3889V A₁ according to claim and a pharmaceutically acceptable carrier.
 9. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic BU-3889V A₂ according to claim 2 and a pharmaceutically acceptable carrier.
 10. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic BU-3889V A₃ according to claim 3 and a pharmaceutically acceptable carrier.
 11. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic BU-3889V D₁ according to claim 4 and a pharmaceutically acceptable carrier.
 12. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic BU-3889V D₂ according to claim 5 and a pharmaceutically acceptable carrier.
 13. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic BU-3889V D₃ according to claim 6 and a pharmaceutically acceptable carrier.
 14. A pharmaceutical composition comprising an amount effective to inhibit the growth of viruses of the antiviral antibiotic complex BU-3889V according to claim 7 and a pharmaceutically acceptable carrier. 